linux-stable/include/linux/time32.h
Arnd Bergmann 9afc5eee65 y2038: globally rename compat_time to old_time32
Christoph Hellwig suggested a slightly different path for handling
backwards compatibility with the 32-bit time_t based system calls:

Rather than simply reusing the compat_sys_* entry points on 32-bit
architectures unchanged, we get rid of those entry points and the
compat_time types by renaming them to something that makes more sense
on 32-bit architectures (which don't have a compat mode otherwise),
and then share the entry points under the new name with the 64-bit
architectures that use them for implementing the compatibility.

The following types and interfaces are renamed here, and moved
from linux/compat_time.h to linux/time32.h:

old				new
---				---
compat_time_t			old_time32_t
struct compat_timeval		struct old_timeval32
struct compat_timespec		struct old_timespec32
struct compat_itimerspec	struct old_itimerspec32
ns_to_compat_timeval()		ns_to_old_timeval32()
get_compat_itimerspec64()	get_old_itimerspec32()
put_compat_itimerspec64()	put_old_itimerspec32()
compat_get_timespec64()		get_old_timespec32()
compat_put_timespec64()		put_old_timespec32()

As we already have aliases in place, this patch addresses only the
instances that are relevant to the system call interface in particular,
not those that occur in device drivers and other modules. Those
will get handled separately, while providing the 64-bit version
of the respective interfaces.

I'm not renaming the timex, rusage and itimerval structures, as we are
still debating what the new interface will look like, and whether we
will need a replacement at all.

This also doesn't change the names of the syscall entry points, which can
be done more easily when we actually switch over the 32-bit architectures
to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to
SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-08-27 14:48:48 +02:00

224 lines
5.7 KiB
C

#ifndef _LINUX_TIME32_H
#define _LINUX_TIME32_H
/*
* These are all interfaces based on the old time_t definition
* that overflows in 2038 on 32-bit architectures. New code
* should use the replacements based on time64_t and timespec64.
*
* Any interfaces in here that become unused as we migrate
* code to time64_t should get removed.
*/
#include <linux/time64.h>
#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
typedef s32 old_time32_t;
struct old_timespec32 {
old_time32_t tv_sec;
s32 tv_nsec;
};
struct old_timeval32 {
old_time32_t tv_sec;
s32 tv_usec;
};
struct old_itimerspec32 {
struct old_timespec32 it_interval;
struct old_timespec32 it_value;
};
extern int get_old_timespec32(struct timespec64 *, const void __user *);
extern int put_old_timespec32(const struct timespec64 *, void __user *);
extern int get_old_itimerspec32(struct itimerspec64 *its,
const struct old_itimerspec32 __user *uits);
extern int put_old_itimerspec32(const struct itimerspec64 *its,
struct old_itimerspec32 __user *uits);
#if __BITS_PER_LONG == 64
/* timespec64 is defined as timespec here */
static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
{
return *(const struct timespec *)&ts64;
}
static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
{
return *(const struct timespec64 *)&ts;
}
#else
static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
{
struct timespec ret;
ret.tv_sec = (time_t)ts64.tv_sec;
ret.tv_nsec = ts64.tv_nsec;
return ret;
}
static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
{
struct timespec64 ret;
ret.tv_sec = ts.tv_sec;
ret.tv_nsec = ts.tv_nsec;
return ret;
}
#endif
static inline int timespec_equal(const struct timespec *a,
const struct timespec *b)
{
return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
}
/*
* lhs < rhs: return <0
* lhs == rhs: return 0
* lhs > rhs: return >0
*/
static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
{
if (lhs->tv_sec < rhs->tv_sec)
return -1;
if (lhs->tv_sec > rhs->tv_sec)
return 1;
return lhs->tv_nsec - rhs->tv_nsec;
}
extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
static inline struct timespec timespec_add(struct timespec lhs,
struct timespec rhs)
{
struct timespec ts_delta;
set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
lhs.tv_nsec + rhs.tv_nsec);
return ts_delta;
}
/*
* sub = lhs - rhs, in normalized form
*/
static inline struct timespec timespec_sub(struct timespec lhs,
struct timespec rhs)
{
struct timespec ts_delta;
set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
lhs.tv_nsec - rhs.tv_nsec);
return ts_delta;
}
/*
* Returns true if the timespec is norm, false if denorm:
*/
static inline bool timespec_valid(const struct timespec *ts)
{
/* Dates before 1970 are bogus */
if (ts->tv_sec < 0)
return false;
/* Can't have more nanoseconds then a second */
if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
return false;
return true;
}
/**
* timespec_to_ns - Convert timespec to nanoseconds
* @ts: pointer to the timespec variable to be converted
*
* Returns the scalar nanosecond representation of the timespec
* parameter.
*/
static inline s64 timespec_to_ns(const struct timespec *ts)
{
return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
}
/**
* ns_to_timespec - Convert nanoseconds to timespec
* @nsec: the nanoseconds value to be converted
*
* Returns the timespec representation of the nsec parameter.
*/
extern struct timespec ns_to_timespec(const s64 nsec);
/**
* timespec_add_ns - Adds nanoseconds to a timespec
* @a: pointer to timespec to be incremented
* @ns: unsigned nanoseconds value to be added
*
* This must always be inlined because its used from the x86-64 vdso,
* which cannot call other kernel functions.
*/
static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
{
a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
a->tv_nsec = ns;
}
static inline unsigned long mktime(const unsigned int year,
const unsigned int mon, const unsigned int day,
const unsigned int hour, const unsigned int min,
const unsigned int sec)
{
return mktime64(year, mon, day, hour, min, sec);
}
static inline bool timeval_valid(const struct timeval *tv)
{
/* Dates before 1970 are bogus */
if (tv->tv_sec < 0)
return false;
/* Can't have more microseconds then a second */
if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
return false;
return true;
}
/**
* timeval_to_ns - Convert timeval to nanoseconds
* @ts: pointer to the timeval variable to be converted
*
* Returns the scalar nanosecond representation of the timeval
* parameter.
*/
static inline s64 timeval_to_ns(const struct timeval *tv)
{
return ((s64) tv->tv_sec * NSEC_PER_SEC) +
tv->tv_usec * NSEC_PER_USEC;
}
/**
* ns_to_timeval - Convert nanoseconds to timeval
* @nsec: the nanoseconds value to be converted
*
* Returns the timeval representation of the nsec parameter.
*/
extern struct timeval ns_to_timeval(const s64 nsec);
extern struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec);
/*
* Old names for the 32-bit time_t interfaces, these will be removed
* when everything uses the new names.
*/
#define compat_time_t old_time32_t
#define compat_timeval old_timeval32
#define compat_timespec old_timespec32
#define compat_itimerspec old_itimerspec32
#define ns_to_compat_timeval ns_to_old_timeval32
#define get_compat_itimerspec64 get_old_itimerspec32
#define put_compat_itimerspec64 put_old_itimerspec32
#define compat_get_timespec64 get_old_timespec32
#define compat_put_timespec64 put_old_timespec32
#endif